Evaluation of the Crack Resistance of Reactive Sintered Composite Boron Carbide-Based Materials

Resumo

The results of studying the crack resistance of reaction-sintered B₄C–SiC composite materials impregnated with liquid silicon with identification and fracture methods are presented. With an increase in the amount of B₄C in the reaction-sintered material, its fragility increases. The crack resistance of the material can be increased from 3.40 to 4.02 MPa·m^1/2 (when tested by different methods) by adding to the composite material up to 30 wt.% SiC. The material is destroyed mainly by the intercrystalline (intergranular) mechanism. Ceramics containing more than 90 wt.% B₄C, is partially destroyed by the transcrystalline mechanism.